Men vs Women- Most classes and gyms are co-ed. If you are uncomfortable being partnered with the opposite sex, be honest with the coach/professor. Whether this is for religious or personal reasons, it is OK to say no to being partnered with the opposite sex. Your coach/professor can only accommodate your preference if you are honest. Women- if the gym does not have any females for you to partner with and this is important for you, consider trying another gym that offers a Women’s only class.
Hygiene- Make sure you don’t smell (check your feet!) and have clean, trimmed nails. Ladies, do not wear makeup that will stain your partner’s gi. Long nails are NOT permitted. Keep your hair out of your face and out of the way for both your and your partner's comfort.
Etiquette- The most common rule that is shared across gyms is no shoes on the mat! Other common rules are standing in line based on rank, bowing, shaking hands, etc. Pay attention to the school’s standard etiquette and follow suit. If you don’t like the formality of certain gyms, you can always choose not to join but remember to respect their customs.
Jewelry- No jewelry on the mats! People often wear rubber rings but no necklaces, earrings, bracelets, etc. Nothing that could scratch or injure yourself or your partner. Additionally, you wouldn’t want to ruin or break any of your jewelry.
Gi vs. No Gi- Make sure you know if the class you are visiting is a gi class or a no gi class. If you have a preference for learning a specific style, do your research before visiting the gym to ensure they offer the type of class you are interested in learning. Some gyms are purely no gi like 10th Planet while many offer both. Some restrict classes to certain levels of training. For example, one gym might only allow students with a minimum of three stripes or a blue belt in the gi to take the no gi class. If no gi is your goal, this is likely not the gym you should check out first as you will be required to train in only the gi until you reach the required level.